牦牛GH基因多态性的PCR-SSCP分析

PCR-SSCP polymorphism of growth hormone gene in the yak

采用PCR-SSCP技术对天祝白牦牛和青海高原牦牛的生长激素基因(GH基因)5个外显子及部分内含子序列进行遗传变异分析,以探讨牦牛GH基因的遗传特性.结果表明:2个牦牛群体GH基因第1、第2和第4外显子无多态性,第3内含子1694bp处均发生T→C转换,形成A、B2个等位基因,并检测到AA、AB和BB共3种基因型;天祝白牦牛第5外显子2373bp处发生G→T碱基颠换,形成C、D2个等位基因,检测到CC和CD2种基因型,但碱基改变并未引起氨基酸变化,因此这种碱基转换为沉默突变;天祝白牦牛和青海高原牦牛均为低度多态,经Hardy-Weinberg平衡检验2个牦牛群体均处于非平衡状态.

Five exons and parts of introns of growth hormone（GH）gene were detected by PCR-SSCP in Tianzhu white yak and Qinghai plateau yak to get molecular genetics information and find the growth character correlation relevance to the molecular.The results indicated that the exon 1,exon 2 and exon 4 did not display polymorphism.The polymorphism of the intron 3 was controlled by A and B alleles and formed three genotypes,namely AA,BB,AB.The result of cloning and sequencing indicated that there was one single nucleotide mutation（T/C）at 1 694 bp in intron 3.For exon 5,two genotypes CD and CC were detected on Tianzhu white yak population.There was one single nucleotide mutation（G/T）at 2 373 bp,and it did not induce the changes of encoding amino acid.Statistical results showed that the GH gene SSCP sites in 2 yak populations were at Hardy-Weinberg disequilibrium（P0.05）,PIC was low polymorphism.